OCR Text |
Show of the calories in the American diet. The shift toward livestock products represents an improve- ment in quality. In addition to calories, a diet should furnish minerals, vitamins, proteins, and other essentials as well as variety. Livestock products are superior to grain products because, in addition to calories, they supply a higher quality of protein and essential calcium and riboflavin. The important question is: What are the prospects of a continuation of the trends shown in table 5? In spite of the bumper crops of recent years, there are still large numbers of the population whose diets are not adequate in nutrition or palatability. Some of the deficiency is due to lack of knowledge and some to habit. But most of it can be attributed to inadequate income. This is shown in table 6, which indicates the dif- ferences in diet which result from the expenditure of larger sums on food. Consumption of live- stock products, fruits, and vegetables increases, while the percentage for grains and potatoes falls off. TABLE 6.-Difference between adequate diets at moderate and liberal costs Source: TJ. S. Department of Agriculture, Bureau of Human Nutrition and Home Economics, based on standards of National Research Council, 1948. Relation of Improved Diets to Land Require- ments.-It should be pointed out that the dietary trends noted are more than a shift toward an ade- quate and more palatable diet. They are also a shift to higher per capita land use. Quantity of food is measured in energy units or calories. When crops go into livestock production rather than directly into human consumption, the cal- orie production per acre is decreased, although other nutritive factors are increased. An ade- quate diet at moderate cost is one in which ap- proximately 45 percent of the total food energy is secured from livestock products, as opposed to the 41 percent so derived since the beginning of World War II. The increase in land requirements since the beginning of the war, due to the inclusion of more livestock products in the diet (see table 5) is 0.14 acres per capita. In a population of 150 million people an increase in cropland require- ments of 0.14 acres per capita is equivalent to a total increase of 21 million acres. Another important shift toward diet improve- ment is the shift to fruits and vegetables. This change, though nutritionally important, does not increase the cropland requirement as much as does the shift to livestock products. The shift to fruits and vegetables, however, increases the demand for irrigated land. * Future Cropland Requirements The previous discussion points out the factors which will operate to increase cropland require- ments in coming years. An indication of past and present land-use needs will be of assistance in arriving at future cropland requirements. These requirements, in turn, will give some indication of the magnitude of the production problem of the next generation. Table 7 shows the trends in total cropland, as well as in the acreage used for export, for work- stock feed, and for domestic consumption, from 1910 to 1950. It also shows the per capita acre- age used to produce for domestic consumption. It indicates that, as cropland has increased, the acreage used for domestic consumption has risen more steeply. During the 40-year period total acreage went up about 10 percent, while that used for domestic consumption rose nearly 50 percent. The difference was due to the sharp decline in acreage devoted to producing feed for work stock. Cropland Needed for Exports.-The land de- voted to export production increased from 1910 157 Percent in diet at- Commodity group M<Sltate Liberal cost Livestock products............................ 45 60 Fruits and green and yellow vegetables______ 8 11 Grains and sweet and white potatoes.......... 33 24 Other foods.................................- 14 15 Total.................................... 100 100 |